Wireless networks continue to evolve as new communication technologies develop and standardize. Wireless network operators can deploy new communication technologies in parallel with earlier generation communication technologies, and wireless networks can support multiple communication technologies simultaneously to provide smooth transitions through multiple generations of mobile wireless devices. Mobile wireless devices can include hardware and software to support wireless connections to different types of wireless networks that use different wireless communication technologies. Wireless networks using different radio access technologies (RATs) can overlap in geographic area coverage, and mobile wireless devices can support connections using different RATs depending on services and/or coverage available. A wireless service provider can provide services to mobile wireless devices through overlapping wireless networks, and mobile wireless devices can connect to one or more of the overlapping wireless networks. In a representative embodiment, a wireless service provider and/or a mobile wireless device can include simultaneous support for a Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) wireless communication protocol and a “legacy” third generation (and/or earlier generation) wireless communication protocol. Representative “legacy” protocols include the Third Generation Partnership Project 2 (3GPP2) Code Division Multiple Access (CDMA) 2000 1x (also referred to as 1xRTT or 1x) wireless communication protocol, the 3GPP Universal Mobile Telecommunications System (UMTS) wireless communication protocol, and the 3GPP Global System for Mobile Communications (GSM) wireless communication protocol.
A dual network mobile wireless device that includes support for both CDMA 2000 1x and LTE is described as a representative device herein. The same teachings, however, can be applied to other mobile wireless devices that can operate in dual (or more generally multiple) wireless communication technology networks. In particular, the teachings disclosed herein can pertain to mobile wireless devices that switch transceivers from one wireless technology to another wireless technology and back again. The teachings provided herein can also apply to mobile wireless devices that operate under widely varying communication channel conditions using a single wireless technology, e.g., when a mobile wireless device encounters a deep fade that interrupts transmission and/or reception between the mobile wireless device and a wireless access network.
Dual chip mobile wireless devices can include separate signal processing chips that each can support a different wireless communication protocol, such as a first signal processing chip for a CDMA 2000 1x wireless network and a second signal processing chip for a LTE wireless network. In particular, in a dual chip mobile wireless device, each signal processing chip can include its own receive signal processing chain, including in some instances multiple receive antennas and attendant signal processing blocks for each signal processing chip. With separate radio frequency receive signaling chains available to each signal processing chip in the dual chip mobile wireless device, paging messages can be received independently from two different wireless networks, such as from the CDMA 2000 1x wireless network and from the LTE wireless network, by the dual chip mobile wireless device. Even when the dual chip mobile wireless device is connected and actively transferring data through one of the signal processing chips to one of the wireless networks, such as the LTE wireless network, the dual chip mobile wireless device can also listen for and receive a paging message through the other parallel signal processing chip from a second wireless access network, such as the CDMA 2000 1x wireless network. Thus, the dual chip mobile wireless device can establish a mobile device originating or mobile device terminating circuit switched voice connection through the CDMA 2000 1x wireless network while also being actively connected to (or simultaneously camped on) a packet switched LTE wireless network. Dual chip mobile wireless devices, however, can consume more power, can require a larger physical form factor and can require additional components (and cost more) than a more integrated “single chip” mobile wireless device.
A single chip mobile wireless device, at least in some configurations, can include a signal processing chip that can support different wireless communications protocols but can be unable to be actively connected to a first wireless access network and to receive communication from a second wireless access network simultaneously. The single chip mobile wireless device can support multiple wireless communication technologies, such as connections to a CDMA 2000 1x wireless network and to an LTE wireless network, but only to one wireless network at any given time. The single chip mobile wireless device can be limited to receiving signals that use one wireless communication technology type at a time, particularly when multiple antennas are used to receive signals for a single communication technology that supports receive diversity. In some embodiments, the single chip mobile wireless device can be referred to as a single radio mobile wireless device, where the “single radio” refers to a radio frequency receive signaling chain that can process one radio frequency technology at a time. In a representative embodiment, a single chip mobile wireless device is able to connect to or camp on an evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (eUTRAN) of an LTE (or LTE-Advanced) wireless network and also to connect to or camp on a radio access network (RAN) of the CDMA 2000 1x wireless network, but not to both wireless networks simultaneously. The single chip mobile wireless device can be registered on both the LTE wireless network and on the CDMA 2000 1x wireless network and can therefore form connections with each wireless network singly but not simultaneously. The single chip mobile wireless device can be connected on the LTE wireless network and can interrupt the connection to the LTE wireless network to maintain registration on the CDMA 2000 1x wireless network. During the interrupted connection, control signaling and responses to received transmissions between the mobile wireless device and the wireless access network portion of the LTE wireless network can be interrupted. Packet transmissions and/or signaling messages from the LTE wireless network to the single chip mobile wireless device can be dropped. For sufficiently long interruptions, the LTE wireless network can drop a connection with the single chip mobile wireless device. Upon returning to the LTE wireless network from the CDMA 2000 1x wireless network, the mobile wireless device can assume a “connected” connection state still exists with the LTE wireless network, while the LTE wireless network can assume an “idle” connection state exists with the mobile wireless device. The LTE wireless network can send signaling messages to the mobile wireless device appropriate for the “idle” connection state, and the mobile wireless device can discard the signaling messages when not appropriate for the “connected” connection state. The performance of higher layer applications can be adversely affected by this misalignment of connection states between the mobile wireless device and the LTE wireless network. Thus, there exists a need to compensate for connection interruptions between a mobile wireless device and a wireless access network to adjust connection states of the mobile wireless device to improve performance of connections between the mobile wireless device and the wireless access network.
This application describes methods by which a mobile wireless device can operate in a multiple wireless network environment and/or a time varying single network environment and adjust connections states after connection interruptions between the mobile wireless device and an access network portion of a wireless network.